a group of afghan police and u.s. troops as they walked through a market. the taliban claimed responsibility. nbc's lester holt is in kabul where he's been reporting for the past week and a half as part of a special nbc news series on region and conflict. lester, you have been on the ground, what is your take away on the green on blue attacks and this suicide attack which is different, at least the taliban taking responsibility? >> well, andrea, it's really in some ways all related that those three troops killed in khost today were operating with afghan national police on a joint patrol. that's part of the exit strategy for the u.s. to hand control over to the afghans. all the time i've been here, commanders have been wanting to demonstrate and show to me these joint patrols and how this transfer is happening. now the closer, of course, u.s. forces work with afghan troops, that, of course, brings into the question these insider attacks which we've been seeing happening more and more. there was a pause for a few weeks, but yesterday, as you noted in eastern afghanistan, an amer